Self-winding watches have been available for many years and are known for keeping a mechanical wrist watch wound by movements of the hand when the watch is worn. Generally, the winding mechanism of a self-winding watch comprises a rotary pendulum or rotor that is connected by means of a gear transmission mechanism to a winding spring, the energy of which is used for driving the escapement mechanism of the watch. The pendulum rotates about its axis on bearings and is capable of making a partial turn or a full-revolution turn.
When the watch is worn, the winding spring of the watch is wound under the effect of the movements of the wearer's hand. When the spring is completely wound, depending on the type of watch, the spring will have energy sufficient to run the watch for 12 to 48 hours. Some watches can store enough energy for a longer time but eventually will stop unless they are rewound. If a person owns more than one watch for use on different occasions, the unused watches remain unwound. Under such conditions, a watch winder may maintain continuous operation for multiple watches.
A watch winder used for self-winding watches is also needed for reducing wear and tear of the moving parts of the watch because a properly designed watch winder can help to distribute the lubricating oil inside the watch evenly for most of the time. When a watch winds down and stops, the lubricating oil inside the watch tends to settle and clot, losing a certain extent of its viscosity over an extended period of time. As a result, the chance of certain moving parts not being properly lubricated when the watch runs again is much greater, resulting in increased friction and pressure for certain moving parts inside the watch and shortened mechanical life and hampered performance. This explains why certain watches in a retail store that remain unwound for a long time do not perform well even though the watches are new. Thus, it is understood why the use of a watch winder is absolutely necessary for self-winding watches kept in stores, exhibitions, and storage collections.
However, the disadvantage of all existing watch winders is that generally they have a rather unattractive appearance and the structure and design of these devices are focused exclusively on provision of the watch-winding function.